[openstack-dev] [Nova][libvirt] Understand why we lookup libvirt domains by instance name

Chris Friesen chris.friesen at windriver.com
Thu May 21 23:18:20 UTC 2015


On 05/21/2015 03:42 PM, Mathieu Gagné wrote:
> On 2015-05-21 3:38 PM, Chris Friesen wrote:
>> On 05/21/2015 03:20 PM, Mathieu Gagné wrote:
>>> On 2015-05-21 3:13 AM, Daniel P. Berrange wrote:
>>>> You do know you can configure the instance name used...
>>>>
>>>> eg in nova.conf
>>>>
>>>>     instance_name_template='inst-%(uuid)s'
>>>>
>>>
>>> Please note that you CANNOT change instance_name_template ones instances
>>> are created otherwise they become unmanageable by Nova. This is because
>>> Nova tries to find the libvirt instance by its name instead of its UUID.
>>> So since instances were spawned with the old value, it won't find
>>> existing instances using the new value.
>>>
>>> And no, I haven't found a way to rename an instance without
>>> redefining/restarting it in libvirt.
>>
>> Is there any reason why we couldn't default to using something like
>> 'inst-%(uuid)s' for the instance name?
>>
>
> I guess it's for the reason I mentioned above:
>
> To not break all OpenStack installations on Earth running with default
> config values.
>

So that's not breaking *upgrades* of all OpenStack installations with default 
config values, which is a slightly different thing.

Chris



More information about the OpenStack-dev mailing list